matrix behavior on array with Proxy

proxy.js

const [width, height] = [10,10]   // 10x10 matrix

const element = (index) => index; 

// lets create the flat array first

const array = Array.from({length: width * height}, (_,index) => element(index));

// lets create the proxy handler
// we return the 'row' of the index by filtering the respective elements
const handler = {
  get: (array, rowIndex) => array.slice(+rowIndex * width, (+rowIndex + 1) * width) 
};

const matrix = new Proxy(array, handler);
const topRow = matrix[0]; // the get handler will be called with (array, "0")
// as matrix[i] now returns the row array, we can now access the array as if it was multidimensional
// topRow should now be [0,1,2,3,4,5,6,7,8,9]
console.log(matrix[3][5]);
// should output 35